Runtime error in my code

#1

https://ide.codingblocks.com/s/140369 This is my code. I amunable to debug it

#2 
import java.util.*;
public class Main {	
    public static void main(String args[]) {
		Scanner sc=new Scanner(System.in);
		int t= sc.nextInt();
             //use while loop to run for all the tc
		while(t>0){
		    int n= sc.nextInt();
            int []arr =new int [n];
            
            for(int i=0;i<n;i++)
                arr[i]  =sc.nextInt();
            
            boolean ans =tell(arr,0,0,0,0);
            
            if(ans)
                System.out.println("Yes");
            else
                System.out.println("No");
            
            t--;
		}
    }
	public static boolean tell(int []arr,int si,int ei,int ans,int len)
	{
		if(si==arr.length)
		{
			if(ans==0 && len>0){//we check that len should be greater than 0 because an empty set is also a subset with sum 0
                return true;
            }else{
                return false;
            }
		}
		return tell(arr,si+1,ei,ans,len)||tell(arr,si+1,ei,ans+arr[si],len+1);
	}
}